The URL Rewriting is a rewriting of URL (adress of the site). It consist in rewriting under simpler shape of the complex URLs (in more readable addresses).The URL Rewriting is transparent for the visitor as well as for the search engines as Google. What notably allows to free yourself from limitations imposed by the robots of indexation on the dynamic URLs with parameters ( What is not the case with GuppY of base which has too many arguments in his addresses). What will have for consequence a better referencing.